title: Risk of fatal pulmonary embolism in patients with treated venous thromboembolism.
abstract: BACKGROUND
  The most serious complication of deep vein thrombosis (DVT) or nonfatal pulmonary embolism (PE) is fatal PE. However, reliable estimates as to the risk of fatal PE in patients with treated DVT or PE are lacking.
  
  
  OBJECTIVE
  To provide reliable estimates of the risk of fatal PE and the case-fatality rate of recurrent DVT or PE among patients presenting with symptomatic DVT or PE, during and following 3 months of anticoagulant therapy.
  
  
  METHODS
  A MEDLINE literature search was performed to identify prospective studies in which patients with symptomatic DVT or PE were treated with 5 to 10 days of heparin and 3 months of oral anticoagulants. We searched the years 1966 to September 1997 using the search terms thrombophlebitis, diagnosis, drug therapy, and prognosis. Current Contents and bibliographies were also scanned.
  
  
  METHODS
  Of 137 retrieved studies, 25 studies satisfied predetermined methodologic criteria and were included in the analysis.
  
  
  RESULTS
  Among patients presenting with DVT, the rate of fatal PE during anticoagulant therapy was 0.4% (95% confidence interval [CI], 0.2%-0.6%); following anticoagulant therapy it was 0.3 per 100 patient-years (95% CI, 0.1-0.8). The case-fatality rate of recurrent DVT or PE during anticoagulant therapy was 8.8% (95% CI, 5.0%-14.1%); following anticoagulant therapy it was 5.1% (95% CI, 1.4%-12.5%). Among patients presenting with PE, the rate of fatal PE during anticoagulant therapy was 1.5% (95% CI, 0.9%-2.2%); following anticoagulant therapy it was 0 per 265 patient-years (95% CI, 0-3.6). The case-fatality rate of recurrent DVT or PE among patients presenting with PE was 26.4% (95% CI, 16.7%-38.1%).
  
  
  CONCLUSIONS
  Among patients with symptomatic PE or DVT who are treated with anticoagulants for 3 months, fatal PE is rare during and following anticoagulant therapy. Patients presenting with PE are more likely to die of recurrent PE or DVT than are patients presenting with DVT.
authors.affiliation: Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: J D
authors.initials: JD
authors.lastname: Douketis
authors.forename: C
authors.initials: C
authors.lastname: Kearon
authors.forename: S
authors.initials: S
authors.lastname: Bates
authors.forename: E K
authors.initials: EK
authors.lastname: Duku
authors.forename: J S
authors.initials: JS
authors.lastname: Ginsberg
mesh_terms: D000925:Anticoagulants / Q000627:therapeutic use; D006493:Heparin / Q000627:therapeutic use; D006801:Humans; D011655:Pulmonary Embolism / Q000188:drug therapy* / Q000401:mortality*; D012008:Recurrence; D012307:Risk Factors; D013223:Statistics as Topic; D013923:Thromboembolism / Q000188:drug therapy* / Q000401:mortality*
chemical_list: D000925:Anticoagulants; D006493:Heparin